Traditional strength training devices are severely limited by design and physics. A variety of methods have been developed over time to strengthen and tone muscles for both health and athletic activity. Conventional exercise emphasizes, and often requires, slow steady movement. In existing devices the forces are generated by weights, springs, or friction and accompanied by the limitations of these force generating methods. These force generating devices are restricted by direction, speed or fixed location. The oldest and most widely used method of strength training is the use of gravitational forces either as “free” weights or as part of an exercise machine. While the countless variations continue to grow, the limitations of weight training remain. Gravitational forces developed by a mass and the kinetic energy of a mass varying with the square of the velocity are both the means and the limits on weight based training. These limitations can result in injury, strengthen slow response muscles and impose higher exercise forces on faster movement.
On the other hand, spring type devices offer a lighter way to generate forces and thus do not have the kinetic energy issues. They have numerous limitations of their own and have not found wide acceptance in athletic training rooms.
Friction type devices are velocity sensitive and exert no forces at a standstill. Some devices use hydraulic dampers as the friction mechanism. One of the largest friction devices is the football blocking sled.
None of the existing devices can simulate athletic conditions or stimulate and develop the quick response muscles required for athletic success. Limitations of existing devices pose additional hazards in rehabilitation therapy.
The limitations of existing exercise equipment make the practice session the most effective method of preparing athletes for competition. This practice endangers player health as the excitement and uncontrollable nature of athletic activities can result in players getting injured. Even when professional players are well matched, drills such as blocking and tackling can aggravate old injuries and cause new ones. Numerous passive devices have been constructed to assist coaches and trainer to improve athletes. The predictability of these devices is their main drawback. The athletic contest is not predictable.
Additionally, instructional devices for athletes have been used that offer limited movement and control of parts of the devices. For example, Burke, et al., U.S. Pat. No. 2,602,666 discloses a blocking dummy, mounted on a trolley that is movable longitudinally of a track. A manual switch is provided for releasing a latch to permit a spring to forcibly and rapidly draw the trolley longitudinally of the track. Foster, et al., U.S. Pat. No. 3,062,548 discloses cylindrical padded members, mounted on a cart having wheels which drive a hydraulic pump for moving hydraulic fluid through a control valve. Kipp U.S. Pat. No. 3,062,547 discloses a defensive reaction football training sled, controlled by the coach. Pate U.S. Pat. No. 5,555,091 and Ballad U.S. Pat. No. 5,752,899 disclose exercise devices submerged in water to resist movement.
Thus, there exists a need for interactive training equipment which would develop strength, agility, and endurance, with reduced risk of injury.